Check for healthy wood, by doing a few bark scrapeings, if its ok then be patient, however if the top growth is dead /brittle then cut away, the damage is possibly down to frost, i have two large topery bay trees which i am watching closely, all the foliage is brown but new growth is appearing that said some bay ive seen are completley gone, and cutting down to a few inches from the ground has been the only option and this may genertate new shoots from lower down assuming the root system is ok. also go easy on the watering, julien.

Don't water it until you see the surface is dry. If it is soaked loosen the compost, without touching the roots, to prevent rotting. If it is not dead it will recover.

I know how you feel, my two bays by the door have done exactly the same thing - i scraped the bark and it is green underneath, but i can't see how they will recover - they look all brown and crispy!